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第114期:100万美元有多重?

来源:可可英语 编辑:Melody   可可英语APP下载 |  可可官方微信:ikekenet

Suppose you're stuck on a desert island with no internet, no books, and an evil genius

假如说你在个荒岛上。没有书,没有因特网,只有个邪恶的天才。

who will only let you off if you can tell him how much a million dollars weighs.

只有你能告诉他一百万美元有多重,他才会放你走。

Luckily, you're a physicist, so you can weigh a million dollars with your mind!

幸亏你是个物理家,因此你可以在脑子里称重量。

Here's how it goes: we approximate.

我们可以估计这个答案。

We don't know how much a dollar weighs, but we do know how big it is… more or less.

我们不知道一块钱多重,但是我们知道它大概多大。

A dollar is about 15 cm long and 5 cm wide…

一块钱是大约15厘米长和5厘米宽。

now how thick is it?

但是它多厚呢?

We don't know that either, but money is made out of paper,

这个我们也不知道,但是我们知道钱是用纸造的。

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and we do know that those 'Harry Potter' books were around 800 pages long, or 400 sheets of paper.

那些哈利波特书都是800页左右,或者说400页纸。

And I think they were about 5 cm thick…

然后我觉得它们是大概5公分厚…

so that gives 80 sheets per cm.

这样每公分里有80页纸。

Now we can find the volume of a dollar: 15 cm long times 5cm wide times one 80th of a cm high

现在我们可以算一块钱的体积:15厘长米乘5厘米宽乘1/80厘米高

is 0.9 cubic centimeters.

是0.9立方厘米。

We still don't know how much paper weighs, though.

我们还是不知道纸多重,

But we do know that a cubic centimeter of water weighs a gram.

但是我们知道一立方厘米水是一克。

And money's a liquid asset, right?

水是个流动性资产,对不对?

So we'll say a cubic centimeter of dollars weighs a gram.

所以我们可以说一立方厘米的美元重一克。

Multiply 0.9 by a million and we're done!

0.9乘100万就行了。

A million dollars weighs 900 kilograms, or two thousand pounds.

一百万美元是900公斤,或者2000英镑。

So why are approximations important in physics?

为什么在物理中估计很重要?

Well, you don't want to attempt a two-month calculation without a ballpark estimate of what you're calculating.

你要做个两月计算前有个大致的估计。

And sometimes approximations like ours can be pretty accurate:

此外,这种估计也可以相当正确:

case in point, according to the US treasury, a million dollars is a ton of money. Literally.

例如,根据美国财政部的说法,一百万美元确实是一吨钱。

重点单词   查看全部解释    
accurate ['ækjurit]

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adj. 准确的,精确的

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genius ['dʒi:njəs]

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n. 天才,天赋

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liquid ['likwid]

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adj. 液体的,液态的
n. 液体

 
multiply ['mʌltiplai]

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vt. 乘,增加
vi. 扩大,繁衍,做乘法<

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calculation [.kælkju'leiʃən]

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n. 计算

 
treasury ['treʒəri]

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n. 国库,宝库 (大写)财政部,国债

 

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